This invention relates to a dual-slope waveform generation circuit for a driver circuit of memory sense amplifiers, and more particularly to a dual-slope waveform generation circuit which uses a time interval of gate input signals of pull-up and pull-down transistors
Generally, a dual-slope waveform generation circuit uses the time interval of two input signals with a same phase. These two input signals, as shown in FIG. 5, provide a dual-slope with an output signal by turning on transistors M.sub.6 and M.sub.7 sequencely. That is, when an input signal IN changes from a low level to a high level, transistor M.sub.6 becomes on by an input signal IN.sub.a so that the first slope is provided with an output signal OUT.sub.c, and transistor M.sub.7 becomes on by an input signal IN.sub.b which has the same phase with said input signal IN.sub.a and a time interval about said input signal IN.sub.a so that the second slope is provided with the output signal OUT.sub.c. In case that the time interval of said input signals IN.sub.a and IN.sub.b is opposite, the output signal still has the dual-slope as described above. On the other hand, there is another dual-slope waveform generation circuit which uses a DC path, as shown in FIG. 6.
In FIG. 6, the first input signal IN.sub.b turns on the transistors M.sub.8, M.sub.9 so that the first slope proportioned to the resistor ratio of said transistors M.sub.8, M.sub.9 is provided with an output signal, and an input signal IN.sub.a which has a time interval with the input signal IN.sub.b turns on transistor M.sub.6 so that the second slope is provided with an output signal.
In the conventional dual-slope waveform generation circuit, as described above, a delay circuit for a time interval of input signals with same phases is required, thus there is a problem that lay out area incrases when a circuit is designed. In the case of using resistor components for the time delay particularly, the increment of layout area becomes the important problem. And in the case of using a DC path, unnecessary power is consumed by the increment of operating current.